A bowling ball is a roun ball made from rubber, urethane, plastic, isinglass, reactive resin (solid, particle, or pearl), or a combination of these materials which is used in the sport of bowling. Ten-pin bowling balls generally have a set of three holes drilled in them, one each for the ring and middle finger, and one for the thumb; however, rules allow for up to five finger holes. A five-pin bowling ball has no finger holes and is smaller so that the bowler can hold the ball in the palm of their hand. Candlepin bowling balls also fit in the hand, but are lighter than five-pin balls.